How to select the right air compressor dryer for your facility

 Selecting the right air compressor dryer is the key to removing damaging moisture and protecting your plant's reliability.

Moisture in compressed air systems is one of the most pervasive and expensive threats to reliability. It’s unavoidable — the air compression process produces condensation and humidity increases in the system. This leads to pipeline corrosion, product contamination and premature wear on attached tools.

An air compressor dryer protects against these threats. It removes moisture from the compressed air lines before it can cause problems. Selecting the right air compressor dryer is a critical decision that can directly impact operations and product quality.

Why dry air matters

When moisture builds up in the compressed air system, it can lead to problems like:

• Rust, corrosion and scale buildup inside of pipes and air receivers.
• The failure of pneumatic tools, as water washes away their lubrication.
• Product contamination (for example, “fisheyes” in paint finishes, clumps in powder conveying).
• Lines freezing in cold weather.

For many industries, even trace moisture can damage expensive equipment, violate safety standards and lead to product recalls.

• Food and beverage : Must abide by strict hygiene standards, requiring compressed air that is free of moisture
• Pharmaceutical : Ultra-dry air is essential for manufacturing and conveying sensitive drugs.
• Electronics : Moisture can cause short-circuiting or corrode sensitive circuitry.
• Automotive : Moisture ruins spray painting and finish work.
• Manufacturing : Water can damage a variety of products.
• Healthcare : Medical gas lines must be completely dry and contaminant-free to ensure patient safety.

There is more than one type of air dryer, and companies must choose which one best suits their operations

Refrigerated air dryers

Refrigerated air dryers are the most common types of dryers, and they use cooling to remove moisture. They work by cooling compressed air to a target temperature (typically 35°F to 40°F), which forces the water vapor to condense into liquid. This liquid water is then collected and removed by a condensate drain.

This method carries some advantages: They require a low initial purchase cost and they have lower operating costs than other methods. They are simple to use and easy to maintain. They provide a stable and consistent dew point that is sufficient for most industrial needs

Refrigerated dryers are the ideal choice for general manufacturing, workshops, automotive service bays and assembly plants. They are available in two main designs:

• Non-cycling : The dryer’s refrigeration circuit runs constantly. This provides simple, reliable performance for facilities where air demand is high and consistent. The ELGi EGRD Series exemplifies these units,

• Cycling : These energy-saving dryers are designed to adjust their cooling effort to match varying air demands. Some models use advanced controls like variable speed drive (VSD), which allows the refrigeration compressor to speed up or slow down to precisely match the cooling load in real-time. Other models, like the ELGi AR Premium Series, use thermal mass control. This method uses the refrigeration system to chill a large, dense material (the “thermal mass”). The main refrigeration circuit cycles off while the stored cold continues to chill the air, making it ideal for facilities with fluctuating air use.

Desiccant air dryers

For applications that require extremely dry air, like in food processing or pharmaceuticals, desiccant dryers are essential. A desiccant dryer passes air through a bed of highly porous desiccant media, grabbing and holding water vapor molecules to strip them from the air. This process is so effective that it can remove nearly all water vapor, enabling the dryer to achieve extremely low dew points like −40°F or −100°F.

The primary advantage of a desiccant dryer is its ability to achieve an ultra-low dew point, which is impossible for a refrigerated dryer.ELGi's HLD Series desiccant dryers are a prime example of this technology, engineered for high reliability and consistent performance in critical applications. These dryers are available in capacities from 10 CFM to 375 CFM and are designed to deliver a consistent -40°F pressure dew point. This level of performance achieves ISO 8573-1:2010 Class 2 air quality.

Key considerations

After deciding between a refrigerated or desiccant dryer, the next step is selecting the right model. This decision hinges on three key considerations: accurate sizing, the required dew point and total cost of ownership.

The most common mistake is matching the dryer's CFM rating directly to the compressor's CFM rating. A dryer advertised for "100 CFM" is rated for a specific set of ideal conditions. A facility’s actual operating conditions are rarely this perfect. On a hot summer day, for example, that same dryer's capacity to remove moisture can drop significantly. Ignoring these real-world variables or intentionally undersizing to save on initial cost will lead to moisture getting past the dryer and damaging downstream equipment.

Secondly, choose an air dryer with pressure dew point (PDP) that is at least 20°F below the lowest ambient temperature your air lines will need. If the pipes are all indoors and protected from cold, a refrigerated dryer is usually sufficient. However, if the pipes are located outdoors or in unheated areas, a desiccant dryer is required to reach a sub-zero dew point that will prevent ice from forming in the lines.

Finally, look at the total cost of ownership (TCO), not just the initial purchase price. A perfect example is comparing a non-cycling refrigerated dryer to a cycling one. The non-cycling model will have a lower initial purchase price. However, it runs at full power 100% of the time, even when air demand is low, leading to a much higher electricity bill. The cycling dryer costs more upfront, but it provides substantial energy savings by matching its power use to the air demand, often resulting in a much lower TCO over its lifetime.

Pattons is your partner

Choosing the right dryer is a critical investment in uptime. Partnering with Pattons ensures you get it right the first time. Our team eliminates the guesswork by performing a detailed system assessment to analyze your precise operating conditions, air demand and purity requirements.

Contact Pattons today to schedule your compressed air assessment and find the perfect ELGi solution for your plant.

Air Dryer comparison